Odor barrier film

ABSTRACT

A multilayer film for ostomy and bowel management applications includes a barrier layer comprising at least about 90% wt. nylon 6/69. The multilayer film provides excellent mechanical and odor barrier properties, and softness and quietness desired in ostomy and bowel management applications.

CROSS-REFERENCE TO RELATED APPLICATION DATA

This application is a continuation application of U.S. patentapplication Ser. No. 14/989,535, filed Jan. 6, 2016, which is acontinuation application of U.S. patent application Ser. No. 13/780,398,filed Feb. 28, 2013, which claims the benefit of and priority to U.S.Provisional Patent Application Ser. No. 61/647,222, filed May 15, 2012entitled, “ODOR BARRIER FILM.”

BACKGROUND

The present disclosure relates to odor barrier materials, and moreparticularly to films and tubes having a layer of an odor barriermaterial for medical uses such as ostomy and bowel managementapplications.

Gas and odor barrier films are known and widely used in the medical andfood packaging industries. Many such films have a barrier layer thatcontains chlorine; other barrier layers are chlorine-free.Chlorine-containing barrier layers use, for example, copolymers ofvinylidene chloride vinyl chloride (VDC-VC) copolymers) and vinylidenechloride methyl acrylate copolymer (VDC-MA copolymers). Thesechlorine-containing films have exceptionally high malodor-causingcompound barrier properties and are typically not adversely affected bythe presence of moisture. One drawback to the use of chlorine-containingcompounds is that these compounds, generally, present environmentalissues in disposal, for example, incineration of materials after use.Another drawback is that specialized equipment is required to processthese materials due to the corrosive nature of the chlorine compounds.

Barrier layers of chlorine-free material include vinyl alcohol basedpolymers, for example, ethylene vinyl alcohol (EVOH) copolymers andpoly(vinyl alcohol) (PVOH). Unfortunately, these materials have beenfound to have reduced barrier performance in the presence of humidity.

Ostomy products and other applications relating to storing andtransporting bodily waste are highly demanding and typically subjectmaterials used in such products to high levels of moisture. At the sametime, it is extremely important that the odor barrier properties of thematerial are and remain high throughout their useful life. In addition,it is imperative that the mechanical strength of the material is alsohigh and remains high for a sufficiently long period of time forextended use of the product.

Other factors and properties that must also be considered in ostomyproduct use are the comfort of the material, as such products are wornnext to the user's body, the flexibility of the material so that itconforms to the user's movements, and the quietness of the product sothat wearing such a product is as audibly imperceptible as possible. Thechlorine-containing materials possess these beneficial properties andqualities, but have the aforementioned environmental issues in disposaland processing.

In an effort to provide a film having the beneficial properties andcharacteristics of VDC-VC, VDC-MA and other chlorine-containingmaterials, without the detrimental effects of these chlorine-containingmaterials, various layered films have been composed of non-chlorinecontaining materials. One known film, disclosed in DE-A-4100350, is aseven layer chlorine-free film for packaging material for infusionsolutions. The material is composed of a base material that is acoextruded film made of an ethylene-vinyl alcohol (EVOH) copolymer andtwo coating polyethylene (PE) layers onto which a PE layer and an EVOHcopolymer layer are extrusion laminated.

One film used in food packaging, disclosed in EP-A-0588667, is amultiple layer film, moisture barrier material that includes a corelayer made of an oxygen barrier material, such as an EVOH copolymer, twointermediate layers provided on the core layer of a propylene (PP)polymer or copolymer or a polymeric adhesive, such as a carboxylic acidor maleic anhydride-modified polyolefin such as polypropylene-basedcarboxylic acid or maleic anhydride-modified polyolefin. Moisturebarrier layers are provided as a blend of a PP polymer or copolymer anda hydrocarbon resin, and outermost layers covering the outer surfacesare also PP polymer or copolymer.

One film used in the manufacture of ostomy pouches, disclosed inInternational application publication WO93/11938, is a five-layerbarrier structure having a gas barrier layer, two moisture barrierlayers and optionally one or more adhesive layers disposed therebetween.The moisture barrier layer is a mesophase PP-based material whichcontacts one or both of the sides of the gas barrier layer. The gasbarrier layer is made of an EVOH copolymer.

Other multi-layer films, such as those disclosed in U.S. Pat. Nos.4,239,826 and 4,254,169, which include an oxygen barrier layer formed ofvinyl alcohol polymer or copolymers (e.g. PVOH, EVOH), and moisturebarrier layers formed of partially hydrolyzed vinyl acetate polymer orcopolymer, or modified polyolefins, are also known. Such films have beenfound to be useful in the manufacture of food packaging containers.

A five layer chlorine-free ostomy pouch film is also known. Such a film,which is disclosed in Giori, U.S. Pat. No. 7,270,860 and is incorporatedherein in its entirety by reference, has a core odor barrier layerformed of a blend or a compound including amorphous polyamide, andanhydride-modified olefin polymer or copolymer. The film also includestwo tie layers on both sides of the core layer and two EVA or EVA-basedsurface layers.

Still another film, disclosed in EP 0700777 B 1, is a chlorine-freecomposition having a gas-barrier layer of a non-chlorine containingorganic polymer which is substantially impermeable to oxygen, two tielayers each contacting one side of the barrier layer, an inner surfacelayer, an outer surface layer and two intermediate layers positionedbetween the surface layers and tie layers. The intermediate layers arean ethylene-propylene copolymer having a flexural modulus (measuredaccording to ASTM D-882) of less than 200 MPa., preferably less than 150MPa.

Multilayer films for ostomy applications including a barrier layercomprising amorphous polyamide also have been developed. For example, WO2011/056861, which is commonly assigned to the assignee of the presentapplication and incorporated in its entirety by reference, disclosessuch a multilayer film. The disclosed multilayer film is chlorine free,and thus, achieves the desired goal with respect to environmentalsafety. Further, it provides a better combination of physicalproperties, including moisture and odor barrier characteristics, tearstrength, comfort and “quietness” when compared to other chlorine freefilms. However, some characteristics of amorphous polyamide, such as itshigh rigidity and high temperature requirements for extrusion, havepresented manufacturing challenges in making and converting themultilayer film. For example, when coextruding the multilayer filmincluding amorphous polyamide, high extrusion temperature for theamorphous polyamide can damage other layers, such as layers comprisingEVA. Further, the hardness of the amorphous polyamide makes it tougherto cut the film and wears cutting knives quickly.

Accordingly, there is a need for a chlorine-free, multi-layer film foruse in ostomy and continence products that provides a barrier formalodor causing compounds, which has more manufacturing friendlyproperties. Desirably, such a film and products made therefrom maintainhigh barrier performance characteristics even in high moistureapplications, for prolonged periods of time. More desirably still, sucha film and products made therefrom exhibit high tear strength, and theproducts exhibit “quietness” when in use.

BRIEF SUMMARY

Odor barrier materials, multilayer films, and tubes for ostomy and bowelmanagement applications are provided according to various embodiments.Such materials, films and tubes include a barrier layer formedessentially from nylon 6/69 to provide excellent mechanical and odorbarrier properties along with softness and quietness desired in ostomyand bowel management applications.

In one aspect, a multi-layer, chlorine-free film for ostomy and bowelmanagement applications is provided. The film includes a barrier layerhaving first and second sides and respectively adjacent first and secondouter layers. The barrier layer includes a low melt polyamide resinhaving a melting temperature between about 125° C. and about 135° C.present in a concentration of about 90% to about 100% by weight (% wt.)of the barrier layer. The barrier layer is substantially impermeable tomalodor causing compounds. Each outer layer is formed from an ethylenevinyl acetate or ethylene methyl acrylate copolymer and blends thereof,or polypropylene-based resins and blends thereof. Each outer layer isarranged on a respective side of the barrier layer.

In one embodiment, the film includes first and second tie layers, eachof which is arranged to contact a side of the barrier layer. The tielayers are formed from a maleic anhydride grafted resin. The resin isone or more of an ethylene-based copolymer, a propylene-based copolymer,an ethylene-octene polymer and a styrene block copolymer. Further, thefilm can also include first and second inner layers. The inner layersare formed from one of an ethylene propylene copolymer (polypropyleneelastomer) based resin, an ethylene-octene based resin and blendsthereof. Each inner layer is arranged to contact a respective tie layer,and each outer layer contacts a respective inner layer.

In some embodiments, the barrier layer is formed from about 100% wt.nylon 6/69. In other embodiments, the barrier layer includes about 90%wt. to about 99% wt. nylon 6/69 and about 1% wt. to about 10% wt.amorphous polyamide. For example, the barrier layer can include about98% wt. nylon 6/69 and about 2% wt. amorphous polyamide.

Further, the thickness of the barrier layer is about 30% to 70% of atotal thickness of the film. In one embodiment, a total thickness of thefilm is between about 60 μm and about 300 μm, and a thickness of thebarrier layer is between about 25 μm and about 90 μm.

In another aspect, an ostomy pouch formed of a film made according toany of the above discussed embodiments is provided. The ostomy pouchincludes two side walls, each of which is formed from the film. Theostomy pouch also includes a stoma-receiving opening on one of the sidewalls. The two side walls are sealed together along peripheral edges ofthe side walls to from the ostomy pouch.

In yet another aspect, a bowel management tube formed of a film madeaccording to above discussed embodiments and having a total thicknessbetween about 230 μm and 270 μm is provided. The film includes a barrierlayer having a thickness between about 60 μm and about 80 μm.

In another aspect, an ostomy pouch formed of a multilayer film isprovided. The multilayer film includes a barrier layer having first andsecond sides, first and second tie layers, and first and second outerlayers. The barrier layer includes a low melt polyamide resin having amelting temperature between about 125° C. and about 135° C. present in aconcentration of about 90% to about 100% by weight (% wt.) of thebarrier layer. The barrier layer is substantially impermeable to malodorcausing compounds. The tie layers are formed from a maleic anhydridegrafted resin. The resin is one or more of an ethylene-based copolymer,a propylene-based copolymer, an ethylene-octene polymer and a styreneblock copolymer. Each outer layer is formed from an ethylene vinylacetate or ethylene methyl acrylate copolymer and blends thereof, orpolypropylene-based resins and blends thereof. Each tie layer isarranged between the barrier layer and a respective outer layer.

In one embodiment, the multilayer film is a five-layer film having atotal thickness between about 90 μm and about 110 μm. The barrier layerhas a thickness between about 35 μm and about 55 μm. In anotherembodiment, the multilayer film is a seven-layer film. The multilayerfilm includes first and second inner layers. The inner layers are formedfrom one of an ethylene propylene copolymer (polypropylene elastomer)based resin, an ethylene-octene based resin and blends thereof. Eachinner layer is arranged between a respective tie layer and a respectiveouter layer. The seven-layer film has a total thickness between about 90μm and about 110 μm, and the barrier layer has a thickness between about35 μm and about 55 μm.

In some embodiments, the barrier layer is formed from about 100% wt.nylon 6/69. In other embodiments, the barrier layer includes about 95%wt. to about 99% wt. nylon 6/69 and about 1% wt. to about 5% wt.amorphous polyamide. Preferably, the thickness of the barrier layermakes up about 35% to 55% of the total thickness of the multilayer film.

Other aspects, objectives and advantages will become more apparent fromthe following detailed description when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The benefits and advantages of the present embodiments will become morereadily apparent to those of ordinary skill in the relevant art afterreviewing the following detailed description and accompanying drawings,wherein:

FIG. 1 is a cross-sectional illustration of a seven-layer film inaccordance with an embodiment of the present disclosure;

FIG. 2 is a cross-sectional illustration of a five-layer film inaccordance with another embodiment;

FIG. 3 is a cross-sectional illustration of a three-layer film inaccordance with yet another embodiment;

FIG. 4 is an illustration of an exemplary ostomy pouch; and

FIG. 5 is an illustration of an exemplary bowel management tube.

DETAILED DESCRIPTION

While the present disclosure is susceptible of embodiment in variousforms, there is shown in the drawings and will hereinafter be describeda presently preferred embodiment with the understanding that the presentdisclosure is to be considered an exemplification and is not intended tolimit the disclosure to the specific embodiment illustrated. The words“a” or “an” are to be taken to include both the singular and the plural.Conversely, any reference to plural items shall, where appropriate,include the singular.

Referring now to the figures and in particular to FIG. 1, there is showna multilayer film 10 according to an embodiment. The film 10 includes abarrier layer 12 formed essentially from low-melt polyamide, preferably,nylon 6/69. The barrier layer is substantially impermeable to malodorcausing compound typically encountered in ostomy pouches. Such malodorcausing compounds can include sulfur containing compounds and indoles.Examples of sulfur-containing compounds include dimethyl disulfide,dimethyl trisulfide, diethyl disulfide, hydrogen sulfide and methylmercaptan. Examples of indoles, and other malodor causing compoundsinclude 3-methyl indole and methanethiol. Other compounds will berecognized by those skilled in the art. Further, the barrier layerimparts tear strength to the film, while at the same time facilitateachieving a “quite”, e.g. low dB(A), film.

The film 10, as shown in FIG. 1, is a seven layer film. The barrierlayer 12 is the thickest layer of the film 10, preferably making up morethan about 25% of the total thickness, and more preferably between about30% and 70% of the total thickness. On either side of the barrier layer12 is a tie layer 14, 16. The tie layers facilitate adhesion of thebarrier layer to the remainder of the film structure. First and secondinner layers 18, 20 are present adjacent to the tie layers 14, 16,respectively. The inner layers provide added tear strength and quietnessfor the film in addition to those properties provide by the barrierfilm. The outermost layers are seal and skin layers 22, 24, that areadjacent the first and second inner layers 18, 20, respectively. Theseal and skin layers provide good sealing characteristics (sealing byheat or other known methods to form a pouch or bag) and are alsocomfortable for application against a user's skin. The film thus has thestructure ABCDCBA, where A represents the skin/seal layer, B representsthe first and second inner layers, C represents the tie layers and Drepresents the barrier layer. Although the film 10 of this embodimentincludes seven layers, in other embodiments, a multilayer barrier filmcan include more than seven layers or less than seven layers. Forexample, a multilayer film according to this disclosure can be asix-layer film including a barrier layer, two tie layers, an innerlayer, and two skin layers (i.e. ABCDCA), or alternatively, a five-layerfilm including a barrier layer, two tie layers and two outer layers(i.e. ACDCA, BCDCB or ACDCB).

Barrier Layer

The barrier layer 12 is formed essentially from a low melt polyamidehaving a melting temperature lower than about 150° C., preferably about125° C. to about 135° C. Preferably, the barrier layer 12 comprises atleast 90% wt. nylon 6/69. Nylon 6/69 is an engineered thermoplasticpolyamide, which is typically manufactured by the condensation ofepsilon-capro-lactam, hexamethylenediamine and azelaic acid. Nylon 6/69is also commonly referred to as PA 6/69. While it is believed that avariety of low melt polyamide resins may be used to form the barrierlayer 12, effective results have been obtained with a nylon 6/69 resinmarketed as Grilon® BM 13 SBG by EMS-Chemie of Sumter, S.C. Grilon® BM13 SBG has a density of about 1.09 grams per cubic centimeter (g/cm³)and a melting point of about 130° C.

The barrier layer 12 comprises nylon 6/69 in an amount greater thanabout 75% by weight, preferably greater than about 85% wt., and morepreferably greater than about 95% wt. As shown in FIG. 1, the barrierlayer 12 is the thickest layer of the film 10, which is configured toprovide excellent odor barrier properties, mechanical (tear) strengthand quietness to the film 10. In one preferred embodiment, the barrierlayer 12 is formed from about 100% wt. nylon 6/69. In anotherembodiment, the barrier layer 12 is formed from a blend comprising about95% wt. to 99.8% wt. nylon 6/69 and about 0.2% wt. to 5% wt. amorphouspolyamide. Amorphous polyamide has a partially aromatic structure and istypically produced by the condensation of an aliphatic diamine with anaromatic diacid, or combination of diacids, in molar amounts equivalentto the diamine used. Partially aromatic nylons such as 6I/6T, MXDI/6I,MXD6/MXDI (wherein I is isophthalic acid, T is terephthalic acid, 6 ishexamethylenediamine, and MXD is metaxylenediamine) may also be mixedwith nylon 6/69 to form the barrier layer 12.

While it is believed that a variety of amorphous polyamide resins may beused, effective results have been obtained with Grivory®, such asGrivory® G21, which is commercially available from EMS-Chemie of Sumter,S.C. Grivory® G21 has a density of about 1.18 g/cm³ and a glasstransition temperature (dry) of about 128° C. Another suitable amorphousnylon resin is Grivory® HB5299, which has a density of about 1.2 g/cm³and a glass transition temperature (dry) of about 95° C. and a meltingpoint temperature of about 219° C. An alternative amorphous nylon,having similar properties a polyamide resin marketed as Selar®, such asSelar® PA3426, by DuPont Company. Selar® PA3426 is understood to besubstantially amorphous with a density of about 1.19 g/cm³ and a glasstransition temperature (dry) of about 127° C. It has high melt strengthand can be used under a broader range of processing conditions thanconventional crystalline nylons.

Tie Layers

The tie layers 14, 16 can be formed of the same material or differentmaterials. In the embodiment of FIG. 1, the tie layers 14, 16 areformulated from the same material. Suitable materials for the tie layersinclude, but not limited to, MAH grafted blend of EPR and PP (e.g.Zelas® MC721 AP from Mitsubishi); MAH grafted or copolymerized EMA, EVA,EBA, EEA or other polyolefins (e.g. Lotader® from Arkema, Bynel® fromDuPont, Plexar® from Lyondellbassell); MAH grafted polypropylene (PP)concentrate (e.g. Bynel® from DuPont) blend with ethylene-propylenecopolymer (PP-elastomer) (e.g. Vistamaxx® from Exxon, Versify® fromDow), ethylene-octene (EO) plastomer (e.g. Exact® from Exxon, Affinity®from Dow), EMA (e.g. Lotryl® from Arkema), or other polyolefins; or GMAgrafted PE, EMA or other polyolefins (e.g. Lotader® from Arkema.) Anolefin-based thermoplastic elastomer (EPR rubber), MAH grafted EMAcopolymers, blends of EMA and MAH grafted linear low densitypolyethylene (LLDPE), PE, EVA copolymers, or ethylene modified withfunctional anhydride groups are believed particularly suitable.

One suitable material for the tie layers is a blend of about 80% of anEMA copolymer having methyl acrylate present at about 18.5% by weight ofthe copolymer and about 20% of a MAH grafted linear low densitypolyethylene (LLDPE), having maleic anhydride present at about 0.8% to1.1% of the MAH-LLDPE polymer. One such EMA polymer is available fromArkema, Inc. as Lotryl® 18MA02. This resin has a melting pointtemperature of 87° C. and a Shore D hardness of 30. One MAH graftedLLDPE is available from DuPont Company under the designation Byner®CXA41E710.

Still another suitable material is a MAH grafted ethylene methylacrylate copolymers (EMA) having maleic anhydride present at about 0.3%and methyl acrylate present at about 20% of the resin. One such materialis available from Arkema, Inc as Lotader® 4503, and has a melting pointtemperature of 78° C. and a Shore D hardness of 25.

Another suitable material for the tie layers is a MAH grafted blend ofEPR and PP available as Zelas® MC721AP, from Mitsubishi Chemical Co.This resin has a melting point temperature of 158° C., a Shore Ahardness of 75 and a specific gravity of 0.89. This resin imparts a highmechanical strength and serves to tie or adhere the barrier layer to theinner and skin/seal layers.

Still another material that is anticipated to be suitable is an epoxyfunctional rubber, such as the above-noted glycidyl methacrylate (GMA)copolymerized with ethylene and other monomers, such as E-MA-GMA(Lotader® AX8920) and E-GMA (Lotader® AX8840).

Inner Layers

The first and second inner layers, 18, 20 can be formulated from thesame material or different materials. In the embodiment of FIG. 1, bothof the first and second inner layers 18, 20 are formed of the samematerial. The inner layers 18, 20 impart added mechanical (tear)strength and quietness to the film 10. Ethylene based polymers, such asethylene vinyl acetate (EVA) copolymer, ethylene-octene (EO) plastomers,and ethylene-propylene (EP) copolymers (PP-elastomer) are suitable filmforming materials for the inner layers. One suitable material is anethylene vinyl acetate (EVA) copolymer having a vinyl acetate content ofabout 8% to 30% and preferably about 10% to about 25%, a melting pointtemperature of about 86° C. and a Shore A hardness of about 91, such asEscorene® FL00218 and Escorene® UL00514, available from ExxonMobilCorporation.

Another suitable material is an EO plastomer having a melting pointtemperature of about 95° C. and specific gravity of about 0.902, such asExact® 0203 resin, also available from ExxonMobil Corporation, which hasa specific gravity of about 0.88 and a Shore A hardness of about 95.This resin is designed for both monolayer and multilayer co-extrudedcast film applications and is suitable in applications that requiretoughness and sealing performance Typical applications include film forindustrial packaging.

Still another suitable resin is an ethylene-propylene copolymer(PP-elastomer) resin that exhibits a low melt flow rate making itsuitable for film application and sealing. It has a low modulus and thusexhibits low noise characteristics. It has excellent compatibility withPP and PE. One such material is available from Dow Chemical from asVersify® 2200. This resin has melting point of about 82° C., a Shore Ahardness of 94 and a Shore D hardness of 42. It has a specific gravityof 0.878. Blends of various PP copolymer resins have also been found tobe suitable, for example, blends of Versify® 2200 and Versify® 3400,which is a similar PP copolymer resin, but has a higher melting point ofabout 97° C., a Shore A hardness of 72 and a Shore D hardness of 22, anda specific gravity of about 0.865. Suitable blends can have ratios ofabout 50% of Versify® 2200 to about 75% of Versify® 2200 by weight ofthe blend. PP-elastomers such as Versify® from Dow, Vistamaxx® fromExxon, and Notio® from Mitsui are also suitable.

Seal/Skin Layers

The seal and skin layers 22, 24 can likewise be formed of the same ordifferent materials. In the embodiment of FIG. 1, the seal/skin layers22, 24 are formed of the same material. These layers are typicallyformed of an ethylene-based polymer or copolymer. Suitable resinsinclude, for example, copolymers of ethylene with vinyl esters, such asvinyl acetate copolymer (EVA) and copolymers of ethylene methyl acrylate(EMA). EVA copolymers contain about 10% to 35% vinyl acetate and morepreferably, about 18% by weight vinyl acetate, by weight of thecopolymer, for example, Escorene® FL00218 and Escorene® UL00514,available from ExxonMobil Corporation. EVA based materials provideincreased comfort for the person using an ostomy pouch made from thismaterial. EVA is also known to exhibit the necessary characteristics forjoining to another EVA member, as by heat sealing or other known sealingmethods, to provide an air-tight, liquid-tight seal at the joint orseal. EVA materials can be blended to facilitate formation and filmextrusion. For example, an EVA blend can have about 98% by weight EVAwith about 2% anti-block and slip additives, in an EVA carrier. Onesuitable additive is available from A. Schulman Inc., as Polybatch®SAB-1982VA.

EMA copolymers include about 10 to about 35% of the methyl acrylate andpreferably about 18.5% to about 30% by weight methyl acrylate, by weightof the copolymer. Such EMA copolymers typically have melting pointtemperatures of about 85° C. to 87° C. and a Shore A hardness of about73 and Shore D hardnesses of about 20 to 25. Suitable materials areavailable from Arkema Inc. as Lotryl® 18AM02 and from DuPont as Elvaloy®1330AC. The EMA resins can also be blended with anti-block and slipadditives in an EVA carrier. One suitable material for blending is theaforementioned Polybatch® SAB-1982VA. Such a blend can have, for exampleEMA at about 98% by weight, with about 2% Polybatch® SAB-1982VAanti-block and slip additive.

As set forth above, other suitable seal and skin layers are formed as ablend of EVA copolymer (Escorene® FL00218 present at 49%) andPP-elastomer (Versify® 2200 present at 49%) with anti-block and slipadditives, and blends of EMA (Elvaloy® 1330AC present at 49%) andPP-elastomer (Versify® 2200 present at 49%) also with anti-block andslip additives. PP-elastomers such as Versify® from Dow, Vistamaxx® fromExxon, and Notio® from Mitsui are also suitable.

Multilayer Films

The multilayer films, such as the film 10 of FIG. 1, can be symmetricalfilms. That is, the layers on opposing sides of the barrier layer,namely the tie layers, inner layers and seal and skin layers areidentical. The thicknesses of the various layers can also be identical.Preferably, the seven-layer film 10 has a thickness between about 60 μmand about 300 μm, and more preferably between about 90 μm and about 260μm. The film 10 includes the barrier layer 12 having a thickness betweenabout 25 micron (μm) and 90 μm, preferably between about 35 μm and 80μm; the tie layers 14, 16, each tie layer having a thickness betweenabout 2 μm and 6 μm, preferably between about 3 μm and 4 μm; the innerlayers 18, 20, each inner layer having a thickness between about 3 μmand about 4 μm, preferably between about 8 μm and about 35 μm; and theskin/seal layers 22, 24, each skin/seal layer having a thickness betweenabout 8 μm and about 70 μm, preferably between about 10 μm and about 60μm. Preferably, the thickness of a barrier layer makes up about 30% toabout 70% of the total thickness of a multilayer film of variousembodiments.

In one embodiment, the seven-layer film 10 has a thickness of about 102μm. The barrier layer 12 is formed from about 100% wt. nylon 6/69(Grilon® BM 13) and has a thickness of about 51 μm. Each of the tielayers 14, 16 is formed from MAH grafted EMA (Lotader® 4503) and has athickness of about 4 μm. Each of the inner layers 18, 20 is formed fromEVA copolymer (Escorene® UL00514) and has a thickness of about 10 μm.Each of the skin/seal layers 22, 24 is formed from a blend comprisingabout 98% wt. EVA copolymer (Escorene® UL00514) and about 2% wt.anti-block and slip additive (Polybatch® SAB-1982VA), and has atthickness of about 11.5 μm.

In another embodiment, the seven-layer film 10 has a thickness of about102 μm. The barrier layer 12 is formed from about 100% wt. nylon 6/69(Grilon® BM 13) and has a thickness of about 38 μm. Each of the tielayers 14, 16 is formed from MAH grafted EMA (Lotader® 4503) and has athickness of about 3 μm. Each of the inner layers 18, 20 is formed fromPP-elastomer (Vistamaxx® 3980FL) and has a thickness of about 12 μm.Each of the skin/seal layers 22, 24 is formed from a blend comprisingabout 98% wt. EVA copolymer (Escorene® UL00514) and about 2% wt.anti-block and slip additive (Polybatch® SAB-1982VA), and has atthickness of about 17 μm.

In yet another embodiment, the seven-layer film 10 has a thickness ofabout 102 μm. The barrier layer 12 is formed from a blend comprisingabout 98% wt. nylon 6/69 (Grilon® BM 13) and about 2% wt. amorphouspolyamide (Grivory® G21), and has a thickness of about 51 μm. Each ofthe tie layers 14, 16 is formed from MAH grafted EMA (Lotader® 4503) andhas a thickness of about 4 μm. Each of the inner layers 18, 20 is formedfrom EVA copolymer (Escorene® UL00514) and has a thickness of about 10μm. The skin/seal layer 22 is formed from a blend comprising about 98%wt. EVA copolymer (Escorene® UL00514) and about 2% wt. anti-block andslip additive (Polybatch® SAB-1982VA), and has at thickness of about11.5 μm. Similarly, the skin/seal layer 24 is formed from a blendcomprising about 98% wt. EVA copolymer (Escorene® UL00514) and about 2%wt. anti-block and slip additive (Polybatch® SAS), and has at thicknessof about 11.5 μm.

In a different embodiment, the seven-layer film 10 has a thickness ofabout 102 μm. The barrier layer 12 is formed from a blend comprisingabout 98% wt. nylon 6/69 (Grilon® BM 13) and about 2% wt. amorphouspolyamide (Grivory® G21), and has a thickness of about 38 μm. Each ofthe tie layers 14, 16 is formed from MAH grafted EMA (Lotader® 4503) andhas a thickness of about 3 μm. Each of the inner layers 18, 20 is formedfrom PP-elastomer (Vistamaxx® 3980FL) and has a thickness of about 12μm. The skin/seal layer 22 is formed from a blend comprising about 98%wt. EVA copolymer (Escorene® UL00514) and about 2% wt. anti-block andslip additive (Polybatch® SAB-1982VA), and has at thickness of about 17μm. Similarly, the skin/seal layer 24 is formed from a blend comprisingabout 98% wt. EVA copolymer (Escorene® UL00514) and about 2% wt.anti-block and slip additive (Polybatch® SAS), and has at thickness ofabout 17 μm.

These embodiments of the seven-layer film 10 are well suited for ostomyapplications, such as an ostomy pouch.

In another embodiment, the seven-layer film 10 has a thickness of about254 μm. The barrier layer 12 is formed from about 100% wt. nylon 6/69(Grilon® BM 13) and has a thickness of about 76 μm. Each of the tielayers 14, 16 is formed from MAH grafted EMA (Lotader® 4503) and has athickness of about 4 μm. Each of the inner layers 18, 20 is formed fromEVA copolymer (Escorene® UL00514) and has a thickness of about 30 μm.Each of the skin/seal layer 22, 24 is formed from a blend comprisingabout 98% wt. EVA copolymer (Escorene® UL00514) and about 2% wt.anti-block and slip additive (Polybatch® SAB-1982VA), and has atthickness of about 55 μm. The seven-layer film 10 of this embodiment isparticularly well suited for bowel management applications. For example,the multilayer film 10 can be formed into a bowel management tube 400(FIG. 5) to provide superior odor barrier performance and excellentmechanical strength. In another embodiment, the layers 12, 14, 16, 18,20, 22, 24 can be coextruded as a multilayer tubing.

FIG. 2 shows a five-layer film 100 according to an embodiment. Thefive-layer film 100 includes a barrier layer 112, two tie layers 114,116, and two skin/seal layers 122, 124. In one embodiment, the film 100has a thickness of about 102 μm. The barrier layer 112 is formed fromabout 100% wt. nylon 6/69 (Grilon® BM 13) and has a thickness of about51 μm. Each of the tie layers 114, 116 is formed from MAH grafted EMA(Lotader® 4503) and has a thickness of about 4 μm. Each of the skin/seallayers 122, 124 is formed from a blend comprising about 98% wt. EVAcopolymer (Escorene® UL00514) and about 2% wt. anti-block and slipadditive (Polybatch® SAB-1982VA), and has at thickness of about 21.5 μm.

In another embodiment, the five-layer film 100 has a thickness of about102 μm. The barrier layer 112 is formed from a blend comprising about98% wt. nylon 6/69 (Grilon® BM 13) and about 2% wt. amorphous polyamide(Grivory® G21), and has a thickness of about 51 μm. Each of the tielayers 114, 116 is formed from MAH grafted EMA (Lotader® 4503) and has athickness of about 4 μm. The skin/seal layer 122 is formed from a blendcomprising about 98% wt. EVA copolymer (Escorene® UL00514) and about 2%wt. anti-block and slip additive (Polybatch® SAB-1982VA), and has atthickness of about 21.5 μm. Similarly, the skin/seal layer 124 is formedfrom a blend comprising about 98% wt. EVA copolymer (Escorene® UL00514)and about 2% wt. anti-block and slip additive (Polybatch® SAS), and hasat thickness of about 21.5 μm.

FIG. 3 shows a three-layer film 200 according to an embodiment. Thethree-layer film 200 includes a barrier layer 212 and two skin layers214, 216. In one embodiment, the film 200 has a thickness of about 4 mil(101.6 μm). The barrier layer 212 is formed from about 100% wt. nylon6/69 (Grilon® BM 13), or a blend comprising about 96% wt. to 98% wt.nylon 6/69 (Grilon® BM 13) and about 2% wt. to 4% wt. amorphouspolyamide (Grivory® G21), and has a thickness of about 1 mil to 2 mil(25.4 μm to 50.8 μm). Each of the skin layers 214, 216 is formed fromMAH grafted EMA (Lotader® 4503) and has a thickness of about 1 mil to1.5 mil (25.4 μm to 38.1 μm).

The multilayer films according to various embodiments of the presentdisclosure can be formed as coextruded sheets. It is anticipated thatthe different thermoplastic resins used for the barrier layer, the tielayers, the inner layers, and the seal/skin layers will be fedcontinuously into respective extruders, melted in the extruders andtransported from a feed-block or combining adaptor into a die where thedifferent polymers, one layer over and adhering to the other, exit thedie slot. Such a coextrusion process or another process for forming sucha film will be recognized by those skilled in the art.

Multilayer films including a barrier layer comprising at least 60% wt.amorphous polyamide, such as those disclosed in WO 2011/056861 haveprovided the advantages of being environment friendly, chlorine-freefilms suitable for ostomy applications, such as ostomy pouches. Althoughsuch films provided suitable properties for ostomy applications, e.g.tear strength, odor and moisture barrier properties, and quietness,manufacturing of the films have been difficult due to high extrusiontemperature required for amorphous nylons. For example, it wasdiscovered that high extrusion temperatures for amorphous nylons havecaused degradation of other film layers, such as layers comprising EVA.Further, amorphous polyamides have a relatively high modulus, and thus,they are difficult to cut and dull cutting knives quickly. Themultilayer films of the present disclosure including a barrier layercomprising about 100% wt. nylon 6/69, which has a melting temperaturecomparable to that of polymeric materials of other layers and lowermodulus than amorphous nylons, eliminate such manufacturing problems andfacilitate the coextrusion process of the multilayer films withoutdamaging other layers.

Further, amorphous polyamides are brittle and noisy when compared tomaterials having lower modulus values. Thus, a thickness of a barrierlayer comprising at least 60% wt. amorphous polyamide is preferably keptunder about 3 μm to provide necessary quietness and softness of the filmfor ostomy applications. On the other hand, the barrier layer of thepresent multilayer films comprising at least 90% wt. nylon 6/69 can be amuch thicker barrier layer, preferably thicker than about 25 μm, toprovide improved mechanical properties, while maintaining quietness andsoftness of the films required for ostomy applications.

The multilayer films 10, 100, 200 can be used to make, for example, anostomy bag or pouch 300, such as that illustrated in FIG. 4. The pouch300 is formed from two sheets of the multilayer film 10, 100, or 200that are heat or otherwise sealed, as at 302 to one another to form anair-tight, liquid-tight pouch. An opening 304 in the pouch permits theaccommodation of, for example, a surgically formed stoma (not shown) forthe inflow of waste into the pouch. The configuration of such a pouchcan be in accordance with the disclosure of the aforementioned U.S. Pat.No. 7,270,860 to Giori. Other configurations of pouches or othercontainers, as well as other uses, will be recognized by those skilledin the art.

Test Results

Several different three-layer film samples including a barrier layercomprising at least about 96% wt. nylon 6/69 and two skin layerscomprising MAH grafted EMA were prepared and tested. Tensile propertiesin both machine direction (MD) and transverse direction (TD), and odorbarrier property test results of the samples and control films(multilayer films including a barrier layer comprising at least 60% wt.amorphous polyamide) are provided in Table 1, below.

Control 1 is a multilayer film having a thickness of about 3.0 mil (76.2μm), which includes a barrier layer comprising polyvinylidene chloride(PVDC). Control 2 is a multilayer film having a thickness of about 4.0mil (101.6 μm), which includes a barrier layer comprising at least 60%wt. amorphous polyamide.

Sample 1 has a thickness of about 4 mil (101.6 μm). The barrier layer212 is formed from about 100% wt. nylon 6/69 (Grilon® BM 13) and has athickness of about 2 mil (50.8 μm). Each of the skin layers is formedfrom MAH grafted EMA (Lotader® 4503) and has a thickness of about 1 mil(25.4 μm).

Sample 2 has a thickness of about 4 mil (101.6 μm). The barrier layer isformed from about 100% wt. nylon 6/69 (Grilon® BM 13) and has athickness of about 1 mil (25.4 μm). Each of the skin layers is formedfrom MAH grafted EMA (Lotader® 4503) and has a thickness of about 1.5mil (38.1 μm).

Sample 3 has a thickness of about 4 mil (101.6 μm). The barrier layer isformed from a blend comprising about 98% wt. nylon 6/69 (Grilon® BM 13)and about 2% wt. amorphous polyamide (Grivory® G21), and has a thicknessof about 2 mil (50.8 μm). Each of the skin layers is formed from MAHgrafted EMA (Lotader® 4503) and has a thickness of about 1 mil (25.4μm).

Sample 4 has a thickness of about 4 mil (101.6 μm). The barrier layer isformed from a blend comprising about 96% wt. nylon 6/69 (Grilon® BM 13)and about 4% wt. amorphous polyamide (Grivory® G21), and has a thicknessof about 2 mil (50.8 μm). Each of the skin layers is formed from MAHgrafted EMA (Lotader® 4503) and has a thickness of about 1 mil (25.4μm).

Sample 5 has a thickness of about 4 mil (101.6 μm). The barrier layer isformed from a blend comprising about 96% wt. nylon 6/69 (Grilon® BM 13)and about 4% wt. amorphous polyamide (Grivory® G21), and has a thicknessof about 1 mil (25.4 μm). Each of the skin layers is formed from MAHgrafted EMA (Lotader® 4503) and has a thickness of about 1.5 mil (38.1μm).

TABLE 1 TENSILE AND ODOR BARRIER TEST RESULTS FOR MULTILAYER FILMSSample Sample Sample Sample Sample Control Control 1 2 3 4 5 1 2 MachineDirection (MD) Tensile Load at Break (lbf) 8.1 4.7 8.1 7.7 5.3 4.4 4.3Tensile Strength (psi) 4092 2415 4263 4005 2738 2938 2206 Elongation (%)607 589 600 618 622 345 181 Energy to Break (in*lbf) 49.8 31.5 49.3 47.835.4 20.9 11.8 Modulus (psi) 14682 7959 17328 15836 9328 26252 25721Transverse Direction (TD) Tensile Load at Break (lbf) 8.0 4.7 8.9 8.65.0 3.5 3.0 Tensile Strength (psi) 4099 2450 4636 4550 2612 2331 1505Elongation (%) 652 679 640 648 650 631 332 Energy to Break (in*lbf) 49.933.5 53.6 53.9 34.3 27.3 16.5 Modulus (psi) 14953 9018 17005 16628 962928109 23960 Gas Chromatography (GC) Odor Testing DMDS*Breakthrough >1440 644 >1440 >1440 >1440 92 >1440 Time (minutes)*DMDS-dimethyl disulfide

As shown in Table 1, the multilayer films including a barrier layercomprising at least 96% wt. nylon 6/69 (Samples 1-5) have improvedtensile properties and significantly lower modulus when compared to themultilayer films including a barrier comprising PVDC or at least 60% wt.amorphous nylon (Control 1-2). Thus, the multilayer films including abarrier layer comprising at least 96% wt. nylon 6/69 provide for astronger, softer and quieter film for ostomy applications whilemaintaining excellent odor barrier properties.

In the present disclosure, all percentages of constituents are byweight, unless otherwise indicated. In the present disclosure, the words“a” or “an” are to be taken to include both the singular and the plural.Conversely, any reference to plural items shall, where appropriate,include the singular. All of the concentrations noted herein aspercentage are percent by weight unless otherwise noted.

From the foregoing it will be observed that numerous modifications andvariations can be effectuated without departing from the true spirit andscope of the novel concepts of the present invention. It is to beunderstood that no limitation with respect to the specific embodimentsillustrated is intended or should be inferred. The disclosure isintended to cover by the appended claims all such modifications as fallwithin the scope of the claims.

What is claimed is:
 1. A multi-layer, chlorine-free film for ostomy andbowel management applications, comprising: a barrier layer having firstand second sides, the barrier layer comprising a low melt polyamideresin having a melting temperature between about 125° C. and about 135°C. present in a concentration of about 90 percent to about 100 percentby weight (% wt.) of the barrier layer, the barrier layer beingsubstantially impermeable to malodor causing compounds; and first andsecond outer layers, each outer layer formed from an ethylene vinylacetate or ethylene methyl acrylate copolymer and blends thereof, orpolypropylene-based resins and blends thereof, wherein each outer layeris arranged on a respective side of the barrier layer.
 2. The film ofclaim 1, further comprising first and second tie layers, the tie layersformed from a maleic anhydride grafted resin, the resin being one ormore of an ethylene-based copolymer, a propylene-based copolymer, anethylene-octene polymer and a styrene block copolymer, wherein each tielayer contacting a respective side of the barrier layer.
 3. The film ofclaim 2, further comprising first and second inner layers, the innerlayers formed from one of an ethylene propylene copolymer (polypropyleneelastomer) based resin, an ethylene-octene based resin and blendsthereof, each inner layer contacting a respective tie layer, wherein theouter layers contact a respective inner layer.
 4. The film of claim 1,wherein the barrier layer is formed from about 100% wt. nylon 6/69. 5.The film of claim 1, wherein the barrier layer comprises about 90% wt.to about 99% wt. nylon 6/69 and about 1% wt. to about 10% wt. amorphouspolyamide.
 6. The film of claim 5, wherein the barrier layer comprisesabout 98% wt. nylon 6/69 and about 2% wt. amorphous polyamide.
 7. Thefilm of claim 1, wherein a thickness of the barrier layer makes up about30% to 70% of a total thickness of the film.
 8. The film of claim 1,wherein a total thickness of the film is between about 60 μm and about300 μm, and a thickness of the barrier layer is between about 25 μm andabout 90 μm.
 9. An ostomy pouch, comprising: two side walls, whereineach of the side walls is formed of the film of claim 1; astoma-receiving opening on one of the side walls; and wherein the twoside walls are sealed together along peripheral edges of the side walls.10. A bowel management tube formed of the film of claim 1, wherein thefilm has a total thickness between about 230 μm and 270 μm, and thebarrier layer has a thickness between about 60 μm and about 80 μm. 11.An ostomy pouch formed of a multilayer film, the multilayer filmcomprising: a barrier layer having first and second sides, the barrierlayer comprising a low melt polyamide resin having a melting temperaturebetween about 125° C. and about 135° C. present in a concentration ofabout 90 percent to about 100 percent by weight (% wt.) of the barrierlayer, the barrier layer being substantially impermeable to malodorcausing compounds; first and second tie layers, the tie layers being amaleic anhydride grafted resin, the resin being one or more of anethylene-based copolymer, a propylene-based copolymer, anethylene-octene polymer and a styrene block copolymer; and first andsecond outer layers, each outer layer comprising an ethylene vinylacetate or ethylene methyl acrylate copolymer and blends thereof, andpolypropylene-based resins and blends thereof, wherein each tie layer isarranged between the barrier layer and a respective outer layer.
 12. Theostomy pouch of claim 11, wherein the multilayer film is a five-layerfilm having a total thickness between about 90 μm and about 110 μm,wherein the barrier layer has a thickness between about 35 μm and about55 μm.
 13. The ostomy pouch of claim 11, wherein the multilayer film isa seven-layer film and further comprising first and second inner layers,the inner layers being one of an ethylene propylene copolymer(polypropylene elastomer) based resin, an ethylene-octene based resinand blends thereof, each inner layer arranged between a respective tielayer and a respective outer layer, wherein the seven-layer film has atotal thickness between about 90 μm and about 110 μm, wherein thebarrier layer has a thickness between about 35 μm and about 55 μm. 14.The ostomy pouch of claim 11, wherein the barrier layer is formed fromabout 100% wt. nylon 6/69.
 15. The ostomy pouch of claim 11, wherein thebarrier layer comprises about 95% wt. to about 99% wt. nylon 6/69 andabout 1% wt. to about 5% wt. amorphous polyamide.
 16. The ostomy pouchof claim 11, wherein a thickness of the barrier layer makes up about 35%to 55% of a total thickness of the multilayer film.